Piperazin quinate and process of making same.



UNITED STATES PATENT OFFICE.

WILHELM CONNSTEIN, OF OHARLOTTENBURG, GERMANY, ASSIGNOR- TO THE FIRM OFBENNO J AFFE, OF MERLINIKENFELDS, GERMANY.

PIPERAZIN QUINATE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 665,879, dated January15, 1901. Applicationfiled June 26, 1899. $erial No. 721,959.(Specimens) To all whom it may concern:

Be it known that I, W ILHELM CONNSTEIN, a subject of the German Emperor,residing at 76 Knesebeckstr'asse, Oharlottenburg, in the Kingdom ofPrussia, German Empire, have invented certain new and usefulImprovements in the Manufacture of Piperazin Quinate and Quinates ofPiperazin Derivatives and their Alkali Salts; and I do hereby declarethe following to be afull, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to a new manufacture of piperazin quinates, underwhich I con1- prehend both the quinate of piperazin proper and thequinates of derivatives of piperazin, such as dimethylpiperazin. Thisproduction of the quinates of piperazins is carried out by employingmolecular proportions of the base and the acid. The reaction in thecase, for example, of the normal salt of piperazins is represented bythe following equation:

Piper-azin. Quinic acid. Quinate of piperazin.

The preparation of the quinates in question may be efiected by causingquinic acid on a piperazin (including, as stated, not only piperazinproper, but its homologues and derivatives also) in molecularproportions to interact.

The quinic acid and the piperazin or one of its derivatives arepreferably mixed in the state of powder and the mixture is heated in anappropriate vessel until it melts, in which condition it is preferablymain tained for some time. The mixture is then allowed to cool andheated with a solvent. The separation of the quinate from the solvent iseffected by one of the methods to be next described for performing thisseparation when the salt is prepared by the reaction of quinic acid onpiperazin proper or one of its homologues or other derivatives insolution; but the solidified mass which contains piperazin quinate maybe used also without treating the same with a solvent. To preparepiperazin quinates, both the compounds which are to be made to react maybe dissolved in the least possible quantity of an appropriate solvent.The solution is advantageously allowed to stand for some hours, (butthis is not absolutely necessary,) and the salt thus formed is separatedby a precipitant or the solvent is eliminated in any suitable manner.

The process can be carried out, for example, as follows: Equivalentquantities of piperazin and quinic acid are dissolved in a minimumquantity of water. The solution is evaporated as much as possible on awaterbath. The remainder of the water is removed by repeated evaporationwith a small quantity of alcohol, the residual salt being then driedinoacuo. According to another method the solution of the piperazinquinate, as concentrated as possible, is mixed with a precipitatingagent, such as absolute alcohol, until no further precipitation takesplace. This fact may readily be noted by adding the alcohol insuccessive small quantities. The quinate thus precipitated is filteredor separated in some other way from, the liquid and dried.

It is advisable when mixing the two compounds to use the base inproportion somewhat greater than the molecular qantity and then to washthe excess of base from the finished product with absolute alcohol.

The compounds produced by the methods above set forth have acidproperties and form salts with alkalies, of which the sodium, potassium,and lithium salts are specially to be noted. These salts are prepared byadding to the aqueous solution of a piperazin quinate, including eitherthe piperazin quinate proper or the quinate of a piperazin derivative,the molecular proportion of sodium carbonate, potassium carbonate, orlithium carbonate and evaporating the solvent.

Piperazin quinates, including the quinate of piperazin proper and thequinates of piperazin derivatives, are white crystalline powders offeebly-acid taste, easily soluble in water, but not in alcohol, being,in fact, precipitated from their aqueous solutions by alcohol. Thesecompounds have valuable medicinal properties, inasmuch as they preventin which formula R and R mean a monovalent radical, the formula of thequin'ate of piperazin proper being:

From the above it will be understood that the terms a piperazin andpiperazinquinate as used in the claims embrace both the piperazin properand the quinate of piperazin proper and the homologues or derivatives ofpiperazin and quinates of the homologues or derivatives of piperazin,respectively, which are equivalent bodies. These bodies may all beclassed under the additional generic designation diethylene-diamins anddiethylene-diamin quinates.

Having now particularly described and ascertained the nature of thisinvention and in what manner the same is to be performed, I declare thatwhat I claim is- 1. The process of preparing piperazin quinates, whichconsists in allowing molecular proportions of a piperazin. and quinicacid to react upon one another.

2. The process of preparing piperazin quin'ates,which consists in mixingmolecular proportions of a piperazin and quinic acid in a asset solventand separating the salt thus produeed.

3. 'llheprocess of preparing a. piperazin quinate which consists inmixing substantially molecular quantities of a piperazin in a solvent,precipitating the resultant quinate by a precipitating agent andseparating it from the liquid.

4. The process of preparing alkali salts of piperazin quinates whichconsists in adding substantially molecular proportions of an alkalicarbonate to a solution of a piperazin quinate and then eliminating thesolvent.

5. The process which consists in mixing substantially molecularproportions of a piperazin and quinic acid in a solvent and separatingthe resultant quinate, then dissolving the latter and addinginsubstantially molecular quantity of an alkali carbonate to the solution, and finally eliminating the solvent.

6. As a new chemical compound a piperazin quinate havingthe generalformula above given which forms white crystalline powders havingfeebly-acid properties and which are soluble in water but not inalcohol.

7. As a new chemical compound, piperazin quinate proper having theformula above given, which formsa white crystalline powder offeebly-acid properties andv which is soluble in .water but insoluble inalcohol.

In testimony whereof I haveaffixed my signature in presence of twowitnesses.

WlLHELM CONN STEIN.

Witnesses:

WOLDEMAR HAUPT, HENRY HAsrER;

